Designing of a non‐fragile robust predictive controller for uncertain systems with time‐varying delay: A delay‐range‐dependent approach

Abstract

This study addresses a new delay‐dependent non‐fragile robust model predictive controller for a class of uncertain continuous‐time systems with time‐varying delay subjected to constrained input and perturbed controller gain. The uncertainties in system parameters and controller gain are considered as general additive forms. The proposed controller can provide a suitable linear feedback control law depending on delay such that robust performance is achieved to the possible existence of uncertainties. To this end, an optimisation problem is formulated to minimise the upper‐bound of the cost function involving some conditions in terms of linear matrix inequalities, utilising the information of lower‐and upper‐bounds of time‐varying delay. By including information regarding the delay range in the quadratic function, the ability to have less conservative results compared to the related works in literature is provided. The effectiveness of the proposed technique is illustrated through a comparison with recent works.